The present invention relates generally to a thermal insulating system for windows. More particularly, the present invention is related to a system adapted to be employed in conjunction with conventional windows which may be switched between light admitting and light blocking, insulative positions. U.S. Classes 88, 160 and 350 are deemed most relevant.
While window fixtures are aesthetically desirable for both residential and commercial buildings, it will be readily appreciated by those skilled in the art that heating and cooling losses caused by windows are extreme. The "R" factor of a single pane window, for example, is approximately one. Double windows may reach an "R" factor or between two and three. This is very poor compared to the "R" factor of a windowless, insulated wall, the characteristic "R" factor of which may vary between eight and twenty depending upon wall thickness and other variables.
Typical window fixtures readily transmit heat, light, and radiant energy. However, window panes are extremely conductive and heat is lost in that manner as well. Loosely fitted windows, particularly where adjustable windows are concerned, experience convective losses.
In the prior art a variety of window blinds or window slat systems are known. A basic venetian blind system is illustrated in U.S. Pat. No. 2,103,271. More sophisticated screen or blind systems; some of which are concerned with the control or energy losses, may be seen in the following U.S. Pat. Nos. 3,946,788; 4,019,554; 1,639,474; and 3,472,305; and 3,443,860. Related devices may be seen in U.S. Pat. Nos. 2,952,312 and 2,804,137. Folding structures employed in conjunction with energy transfer are illustrated in U.S. Pat. Nos. 2,310,086 and 3,048,375. The latter patent teaches that a plurality of slates may be moved between open and closed positions to variably effect energy transmission.